I am amused to see that Alan Greenspan, the former US Federal Reserve chairman, is quoted in The Times thus wrt the recent/ongoing financial crisis:
"It's human nature, unless somebody can find a way to change human nature, we will have more crises and none of them will look like this because no two crises have anything in common, except human nature."
I agree, humans always delude themselves into thinking that boom times can be perpetual; they never are.
Even our "respected" and "decisive" prime minister was deluded, being on the record as saying that he had put an end to "boom and bust".
I wonder what other delusions he holds?